Field of the Invention
The present invention relates to a developing cartridge configured to be installed to an image forming apparatus adopting an electro-photographic type.
Description of the Related Art
There is conventionally known an image forming apparatus of an electro-photographic type to which a developing cartridge is detachably installed. Such an image forming apparatus is provided with a new or unused cartridge detection means for judging as to whether or not the installed developing cartridge is new.
For example, a laser printer is provided with a developing cartridge and a detecting mechanism, the developing cartridge including a detection objective rotating part and an agitator gear, and the detecting mechanism including an actuator and an optical sensor (photodetector). The detection objective rotating part has a detection objective portion. When the developing cartridge is installed to a body casing in the laser printer, driving force is transmitted to the detection objective rotating part via the agitator gear. The driving force rotates the detection objective rotating part, which causes the detection objective portion to abut against the actuator, and thereby swinging the actuator. Then, the optical sensor detects the swing of the actuator, and the laser printer judges whether or not the developing cartridge is new based on the detection result (for example, see Japanese Patent Application Laid-open No. 2012-108537).